System of underground conductors for electrical distribution



(No Model.) T. A. EDISON.

SYSTEM OF UNDERGROUND CONDUCTORS FOR ELECTRICAL DISTRIBUTION,

No. 273,828. Patented Mar. 13,1883.

WITNESSES INVENTOR:

. eff/M I gg $74 ATTORMYQ N. PEIERS, Phola-Limoqnphar. wa-hinmn. n. c

UNITED STATES PATENT OFFICE.

THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.

SYSTEM OF UNDERGROUND CONDUCTORS FOR ELECTRICAL DlSTRlBUTlON.

SPECIFICATION forming part of Letters Patent No. 273,828, dated March13, 1883.

Application filed August 7, 1882.

- that the following is a full and exact description of the same,reference being had to the accompanying drawing, and to the letters ofreference marked thereon.

I have proposed heretofore, in la yin g the conductors for mymultiple-arc system of electrical distribution, to connect theintersecting conductors at each crossing of two streets at four pointsby runningtheminto fourjunctionboxes located at the corners of theblocks or squares, the positive conductors being in this way allconnected together, and likewise all the negative conductors, the wholeforming a double net-work of intersecting and connected conductors. Eachtube was run into aseparate box near each corner, and a fusibleconductor or safety-catch placed in the line of one or each conductor.This plan is set forth in application for patent filed by me October 4,1881, (Serial No. 43,162.)

The object of the present arrangement is to produce a more convenientmanner of arranging and connecting the conductors at the intersection oftwo streets, making them more accessible for repairs of connections,replacement of satiety-catches, or for testing purposes. This Iaccomplish by connecting the conductors of the eight pairs of conductorsat each street intersection and locating the safetycatchesatonepoint.Forthispurposetheeight tubes carrying the conductors are run to thecenter of the street intersection, and there enter a single box in whichthe positive conductors are connected together, as well as the negativeconductors, and in which a fusible conductor or safety-catch is placedin the line of each of the positive or negative conductors, or both.This box is provided with a hand-hole and cover at the surface of thepavement for giving easy access to the connections. A similar method ofconnecting the conductors may,

(No model.)

if desired, be employed where one street runs into another withoutcrossing, in which case only six tubes instead of eight would enter thebox.

The foregoing will be better understood from the drawing, which is a topview of the parts, the junction-box beingin horizontal section. I

A B G D are four blocks or squares, along the sides of which run thetubes at b c d efg I1, each carrying a pair of conductors, l 2. Fromcoupling or service boxes E, near corners of the blocks or squares,tubes 43 70 l m n 01) 1 run to a box, F, at the center of theintersection of the streets, such tubes being bent to the proper curvefor the purpose, which bending does not affect the insulation of theinelosed conductors. The tubes enter the sides of the box F, and theconductors projecting from such tubes are connected to rings or plates PN. Safety-catches or sections of fusible conductor 8 are connected inthe line of the positive or negative conductors, or both, within the boxF, which safety-catches melt and break the circuit when the flow ofcurrent becomes abnormal and before damage is done. The junction-box Fhas a hand-hole and cover at the surface of the pavement, to give accessto the connections.

hat I claim is-- 1. In a system of underground conductors for electricaldistribution, the combination of positive and negative conductorsforming com plete metallic circuits, laid on opposite sides ofintersecting streets, with connections between all the positiveconductors and connections between all the negative conductors of thetwo streets, said connections being made at one point, to which all theconductors run, substantially as set forth.

2. 111 a system of underground conductors for electrical distribution,the combination of positive and negative conductors, laid in intersecting streets and forming complete metallic circuits, withconnections between all of the positive conductors and connections between all the negative conductors of the two streets, said connectionsbeing made at one point, to which all the conductors run, and fusi- Iwhich all the conductors are connected, suhble safety-catches in theseveral circuits at staniially as set forth. IO such point,sul'istantially as set forth. This specification signed and witnessedthis I 3. The combination, with the tubes laid on 2241 day of May, 1882.

5 each side of'intersccting streets and the pairs 1 THOMAS A. EDISON.

of conductors incloseil therein, of a single cen- Witnesses: tral boxinto which all of such tubes run, and EDWARD G. ROWLAND, 7 twopole-plates Within such central box, to i U. P. MOTT.

